Installing with package save mode "nuspec" always reinstalls

[joelverhagen]

Steps

nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nuspec
nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nuspec

-or-

nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nupkg -OutputDirectory packages
nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nupkg -OutputDirectory packages

Expected

The package should only be installed once.

The following steps act as expected:

nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nupkg
nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nupkg

> nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nupkg
Feeds used:
  C:\Users\jver\AppData\Local\NuGet\Cache
  C:\Users\jver\.nuget\packages\
  https://api.nuget.org/v3/index.json

Attempting to gather dependency information for package 'Newtonsoft.Json.8.0.3' with respect to project 'C:\trash\2016-03-25\nupkgRepro', targeting 'Any,Version=v0.0'
Attempting to resolve dependencies for package 'Newtonsoft.Json.8.0.3' with DependencyBehavior 'Lowest'
Resolving actions to install package 'Newtonsoft.Json.8.0.3'
Resolved actions to install package 'Newtonsoft.Json.8.0.3'
Adding package 'Newtonsoft.Json.8.0.3' to folder 'C:\trash\2016-03-25\nupkgRepro'
Added package 'Newtonsoft.Json.8.0.3' to folder 'C:\trash\2016-03-25\nupkgRepro'
Successfully installed 'Newtonsoft.Json 8.0.3' to C:\trash\2016-03-25\nupkgRepro

> nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nupkg
Feeds used:
  C:\Users\jver\AppData\Local\NuGet\Cache
  C:\Users\jver\.nuget\packages\
  https://api.nuget.org/v3/index.json

Package "Newtonsoft.Json.8.0.3" is already installed.

Actual

The package is installed twice. The second install overwrite all of the files on disk, but is effectively a no-op.

> nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nuspec
Feeds used:
  C:\Users\jver\AppData\Local\NuGet\Cache
  C:\Users\jver\.nuget\packages\
  https://api.nuget.org/v3/index.json

Attempting to gather dependency information for package 'Newtonsoft.Json.8.0.3' with respect to project 'C:\trash\2016-03-25\nuspecRepro', targeting 'Any,Version=v0.0'
Attempting to resolve dependencies for package 'Newtonsoft.Json.8.0.3' with DependencyBehavior 'Lowest'
Resolving actions to install package 'Newtonsoft.Json.8.0.3'
Resolved actions to install package 'Newtonsoft.Json.8.0.3'
Adding package 'Newtonsoft.Json.8.0.3' to folder 'C:\trash\2016-03-25\nuspecRepro'
Added package 'Newtonsoft.Json.8.0.3' to folder 'C:\trash\2016-03-25\nuspecRepro'
Successfully installed 'Newtonsoft.Json 8.0.3' to C:\trash\2016-03-25\nuspecRepro

> nuget.exe install Newtonsoft.Json -Version 8.0.3 -PackageSaveMode nuspec
Feeds used:
  C:\Users\jver\AppData\Local\NuGet\Cache
  C:\Users\jver\.nuget\packages\
  https://api.nuget.org/v3/index.json

Attempting to gather dependency information for package 'Newtonsoft.Json.8.0.3' with respect to project 'C:\trash\2016-03-25\nuspecRepro', targeting 'Any,Version=v0.0'
Attempting to resolve dependencies for package 'Newtonsoft.Json.8.0.3' with DependencyBehavior 'Lowest'
Resolving actions to install package 'Newtonsoft.Json.8.0.3'
Resolved actions to install package 'Newtonsoft.Json.8.0.3'
Adding package 'Newtonsoft.Json.8.0.3' to folder 'C:\trash\2016-03-25\nuspecRepro'
Added package 'Newtonsoft.Json.8.0.3' to folder 'C:\trash\2016-03-25\nuspecRepro'
Successfully installed 'Newtonsoft.Json 8.0.3' to C:\trash\2016-03-25\nuspecRepro